• M1/M2
• IBA1
• comportamento biologico
• CD204
• carcinomi mammari
• cane
• prognosi
• TAM

The tumour microenvironment plays an important role in the behaviour of malignant solid tumors. Among cells associated with this, tumor associated macrophages (TAMs) are the most influential for tumour progression. Preliminary studies demonstrated that CD204-positive macrophages might affect the development and behaviour of canine mammary carcinomas (CMCs). We investigated the relationship between presence of M1 and M2 response and different pathological features and tumour progression in CMCs. The expression of Iba1+ and CD204+ TAMs was immunohistochemically and morphometrically quantified in 60 CMCs and the relationship among the presence of Iba1+ and CD204+cells and histological subtype, histological grade, clinical obesity index and tumour progression was investigated. In solid CMCs there was a significantly higher count of total (p<0.003) and CD204+ macrophages (p<0.0001). The presence of total and CD204+ macrophages was significantly higher in grade III than in grades I and II CMCs (p<0.0001) and in CMCs with lymphatic invasion (p<0.0001). The presence of higher counts of CD204+ macrophages characteristic of a M2 response was associated with a poorer prognosis. Bitches bearing CMCs with a M1 response had a mean survival time of 715±6 days, while subjects bearing CMCs with a M2 response 462±18 days. The results of our study confirm that the presence of a M2 response in CMCs is associated with a more aggressive histotype, higher histological tumour grade, presence of lymphatic invasion and strongly suggest the potential of CD204 as a prognostic factor for CMCs.